A battery pack formed of a secondary battery has been conventionally used as a battery for a hybrid vehicle or an electric vehicle. Since the secondary battery generates heat during charge and discharge and the like to, the performance of the battery may be degraded and the life thereof may be shortened.
To address this, the secondary battery may be cooled by bringing a cooling medium into contact with the secondary battery placed in the battery pack.    [Patent Document] International Publication WO98/32186